The present invention relates to means for connecting at least one breathing gas cylinder to a face mask or the like in breathing equipment of the kind used by fireman and divers, for instance.
Very high requirements are placed on breathing equipment of the kind normally used in difficult and dangerous circumstances. In particular, such breathing equipment must be easy to handle and to be safe and reliable in use. Such equipment shall also be capable of withstanding rough treatment and must be flexible in solving problems that arise in emergency situations.
The breathing gas is normally obtained from a back-carried gas cylinder which when full can have a pressure of 300 bars. The equipment includes one or more pressure regulators by means of which the air pressure is lowered to an overpressure corresponding to about 245 Pa (25 millimeters water column) when entering a face mask, mouthpiece or the like.
Depending on the type of working operation concerned, the user of the equipment will carry either one single air supply cylinder or two mutually connected cylinders, this latter in order to extend the working capacity of the equipment. When only a single cylinder is used, it is desirable to be able to quickly refill the cylinder as the need arises with the cylinder constantly connected to the breathing equipment. When using a single gas tube, it should be possible in emergency situating to connect the cylinder temporarily to, corresponding breathing equipment carried by another person. When using two cylinders, the cylinders will preferably be mutually connected with the aid of a device which will permit the relative positions of the cylinders to change and enable cylinders of mutually different diameters to be used.
The main object of the present invention is to provide simple and reliable means for connecting at least one gas cylinder to a face mask or like device, the means being constructed to fulfil the aforesaid requirements, among others. The connection means shall also be relatively insensitive to external forces.
WO 95/03092 discloses a means for coupling a breathing gas cylinder to a face mask wherein at least one of the coupling connectors can be adjusted angularly in relation to the remaining connector. However, a connector not used may cause problems in certain situations as it can not be pivoted to a protected parking position.
According to the present invention, these objects are achieved by the means for coupling at least one breathing gas cylinder to a face mask as described hereinafter.
The fact that not all connections are fixed enables the connector means to be connected-up more easily when two cylinders are both to be connected commonly to a breathing mask. Among other things, the cylinders need not necessarily be fully parallel with one another or located at precisely the same height. The inventive connector means also enables cylinders of different diameters to be used together. Furthermore, the connectors means also provides from a safety aspect the very important advantage of enabling abrupt movements of the gas cylinders to be taken up by the connector means with no risk of leakage that would otherwise occur if the cylinders were to be rigidly connected together. Such abrupt movement of the cylinders may be the result of careless handling of the cylinders, for instance dropping the cylinders onto the floor so as to cause the cylinders to shift relative to one another.
When only one single gas cylinder is connected to the air supply system and the additional angularly adjustable pipe connection is intended to be used to quickly replenish the cylinder or to enable further breathing equipment to be connected to the cylinder, the ability of being able to pivot the pipe connection to ba protected packing position when not used for the aforesaid purpose is of great benefit.
Particularly advantageous embodiments of a connector means described hereinafter.
The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawings, in which
FIG. 1 illustrates a fireman using breathing equipment which includes an inventive connector means;
FIGS. 2 and 3 illustrate the inventive means in two different operational states; and
FIGS. 4 and 5 illustrate the connector means for FIGS. 2 and 3 from beneath and partly in section.